The IEEE 1149.1 Test Access Port (TAP) is used widely in the semiconductor industry as an IC interface for controlling many types of embedded IC circuits, such as but not limited to test circuits, debug circuits, programming circuits, instrumentation circuits and trace circuits. The TAP has proven for the last 20 years to be effective in controlling the operations of embedded IC circuits. However, the TAP has not proven to be effective in controlling the operations of embedded IC circuits that depend on at-speed Update & Capture and Shift & Capture operations. The first part of this disclosure (FIGS. 1-7) describes the at-speed Update & Capture and Shift & Capture problem. The second part of this disclosure (FIGS. 8-41) describes novel solutions to this problem using various examples of implementation.